Semiconductor workpiece carriers and methods for processing semiconductor workpieces

ABSTRACT

Semiconductor workpiece carriers and methods for processing semiconductor workpieces are disclosed herein. In one embodiment, a semiconductor workpiece carrier assembly includes (a) a support structure having an opening sized to receive at least a portion of a semiconductor workpiece, and (b) a replaceable carrier positioned at the opening. The replaceable carrier includes a base and an adhesive layer on the base. The base has a surface, and the adhesive layer covers only a section of the surface of the base. The adhesive layer releasably attaches the replaceable carrier to the support structure.

TECHNICAL FIELD

The present disclosure is related to semiconductor workpiece carriersand methods for processing semiconductor workpieces.

BACKGROUND

Processors, memory devices, imagers, and other types of microelectronicdevices are often manufactured on semiconductor workpieces or othertypes of workpieces. In a typical application, several individual dies(e.g., devices) are fabricated on a single workpiece using sophisticatedand expensive equipment and processes. Individual dies generally includean integrated circuit and a plurality of bond-pads coupled to theintegrated circuit. The bond-pads provide external electrical contactson the die through which supply voltage, signals, etc., are transmittedto and from the integrated circuit. The bond-pads are usually verysmall, and they are arranged in an array having a fine pitch betweenbond-pads. The dies can also be quite delicate. As a result, afterfabrication, the dies are packaged to protect the dies and to connectthe bond-pads to another array of larger terminals that is easier toconnect to a printed circuit board. The package can then be electricallyconnected to other microelectronic devices or circuits in many types ofconsumer or industrial electronic products.

Electronic product manufacturers are under continuous pressure to reducethe size of their products. Accordingly, microelectronic diemanufacturers seek to reduce the size of the packaged dies incorporatedinto the electronic products. One approach to reducing the size ofpackaged dies is to reduce the thickness of the dies. For example, thebackside of a wafer is often ground to reduce the thickness of the diesformed on the wafer. After backgrinding, the wafer is attached to a dieattach film tape and then cut to singulate the dies. The die attach filmtape includes a base and an adhesive layer on the base. Aftersingulation, the dies are removed from the base and placed on a carriertape for temporary storage. When the dies are removed from the base,sections of the adhesive layer remain attached to corresponding dies tofacilitate subsequent attachment of the dies to a substrate forpackaging. Conventional carrier tapes include a base and an adhesivelayer on the base. For purposes of brevity and clarity, in this sectionthe adhesive layer of the die attach film tape that remains attached tothe dies will be referred to as the die attach adhesive, and theadhesive layer of the carrier tape will be referred to as the carriertape adhesive. The singulated dies are attached to the carrier tape withthe die attach adhesive facing the carrier tape adhesive.

One drawback of conventional carrier tapes is that each die needs to beremoved from the carrier tape after a relatively short time (e.g., twoto three weeks) because the bond between the die attach adhesive and thecarrier tape adhesive strengthens over time. If a die is stored on acarrier tape for too long, several problems may result. First, removingthe die can cause delamination between the die and the die attachadhesive because the bond between the die attach adhesive and thecarrier tape adhesive may be stronger than the bond between the dieattach adhesive and the die. Second, an increased force is required toseparate the die from the carrier tape, and the increased force cancrack or otherwise damage the die. Third, sections of the carrier tapeadhesive may remain attached to the die attach adhesive after the die isremoved, which reduces adhesive strength of the die onto the substrateor leadframe. The may result in delamination of the die from thesubstrate or leadframe due to insufficient adhesion to the latter.Accordingly, there is a need to improve the processing of semiconductorworkpieces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top plan view of a carrier assembly for processingsemiconductor workpieces in accordance with one embodiment of thedisclosure.

FIG. 1B is a schematic side cross-sectional view of the carrier assemblytaken generally along the line 1B-1B of FIG. 1A.

FIG. 2A is a top plan view of the carrier assembly with a plurality ofsemiconductor components attached to the replaceable carrier.

FIG. 2B is a schematic side cross-sectional view of the carrier assemblyand the semiconductor components taken substantially along the line2B-2B of FIG. 2A.

FIG. 3 is a schematic side cross-sectional view of the carrier assemblywith a semiconductor workpiece attached to the assembly.

FIG. 4 is a schematic side cross-sectional view of a carrier assembly inaccordance with another embodiment of the disclosure.

FIG. 5 is a top plan view of a carrier assembly for processingsemiconductor workpieces in accordance with another embodiment of thedisclosure.

DETAILED DESCRIPTION

Specific details of several embodiments of the disclosure are describedbelow with reference to semiconductor workpiece carriers and methods forprocessing semiconductor workpieces. The semiconductor workpiecesinclude substrates upon which and/or in which microelectronic devices,micromechanical devices, data storage elements, optics, read/writecomponents, and other features are fabricated. For example, SRAM, DRAM(e.g., DDR-SDRAM), flash-memory (e.g., NAND flash-memory), processors,imagers, and other types of devices can be constructed on semiconductorworkpieces. The semiconductor workpieces can be semiconductor wafers,glass substrates, dielectric substrates, or many other types ofsubstrates. Moreover, several other embodiments of the invention canhave different configurations, components, or procedures than thosedescribed in this section. A person of ordinary skill in the art,therefore, will accordingly understand that the invention may have otherembodiments with additional elements, or the invention may have otherembodiments without several of the elements shown and described belowwith reference to FIGS. 1A-5.

In one embodiment shown in FIGS. 1A and 1B, a semiconductor workpiececarrier assembly 100 includes (a) a support structure 110 having anopening sized to receive at least a portion of a semiconductorworkpiece, and (b) a replaceable carrier 130 positioned at the opening.The replaceable carrier 130 includes a base 132 and an adhesive layer140 on the base. The base 132 has a surface, and the adhesive layer 140covers only a section of the surface. The adhesive layer also releasablyattaches the replaceable carrier to the support structure.

FIG. 1A is a top plan view of a carrier assembly 100 for processingsemiconductor workpieces in accordance with one embodiment of thedisclosure. FIG. 1B is a schematic side cross-sectional view of thecarrier assembly 100 taken generally along the line 1B-1B of FIG. 1A.Referring to both FIGS. 1A and 1B, the carrier assembly 100 isconfigured to temporarily support or carry a semiconductor workpiece, ora portion of such a workpiece (e.g., a microelectronic die) duringand/or between processing procedures. For example, the carrier assembly100 may support a semiconductor workpiece during a dicing procedure asillustrated below in FIG. 3, or the assembly 100 may carry a pluralityof microelectronic dies after a wafer reconstruction process asillustrated below in FIGS. 2A and 2B. In either case, after the carrierassembly 100 temporarily supports the semiconductor component(s), thecomponent(s) can be removed from the assembly 100.

The carrier assembly 100 of the illustrated embodiment includes asupport structure 110 and a replaceable carrier 130 releasably attachedto the support structure 110. The support structure 110 can include agenerally annular frame having an inner surface 112, an outer surface114 opposite the inner surface 112, a first surface 116 (FIG. 1B), and asecond surface 118 opposite the first surface 116. The illustrated innersurface 112 defines a generally circular opening 120 sized to receive asemiconductor workpiece. In other embodiments, however, the innersurface 112 of the support structure 110 can have a differentconfiguration. For example, the support structure may not have agenerally annular shape, and/or the opening may be sized to receive onlya portion of a workpiece.

The replaceable carrier 130 of the illustrated embodiment is releasablyattached to the first surface 116 of the support structure 110 andextends across the opening 120. The illustrated replaceable carrier 130includes a base 132 and an adhesive layer 140 on a portion of the base132. The base 132 can be a generally flexible film having a first majorsurface 134 facing the support structure 110 and a second major surface138 opposite the first major surface 134. The first major surface 134has a central portion 136 a and a generally annular perimeter portion136 b outboard the central portion 136 a.

The adhesive layer 140 is disposed on the perimeter portion 136 b of thefirst major surface 134 and attaches the base 132 to the supportstructure 110. In the illustrated embodiment, the adhesive layer 140 isnot disposed on the central portion 136 a of the first major surface 134such that the central portion 136 a is exposed. As a result, the centralportion 136 a of the first major surface 134 can provide a supportsurface to which a semiconductor component or workpiece can be directlyattached. In other embodiments, the adhesive layer 140 can be disposedon one or more sections of the central portion 136 a. In either case,the adhesive layer 140 covers only a portion of the first major surface134 so that a section of the surface 134 is exposed.

The adhesive layer 140 enables the replaceable carrier 130 to beselectively detached from the support structure 110 so that the supportstructure 110 can be reused with another replaceable carrier 130. Forexample, in several applications, the replaceable carrier 130 may beused to support a single workpiece and, after the workpiece is detached,the carrier 130 can be decoupled from the support structure 110 and asecond releasable carrier 130 can be attached to the support structure110. In other applications, the replaceable carrier 130 may be reusedwith several different workpieces. In either case, the adhesive layer140 can include a UV-curable adhesive or other suitable adhesive thatcan be manipulated to selectively release the replaceable carrier 130from the support structure 110.

FIGS. 2A-3 illustrate different methods of processing semiconductorcomponents and/or workpieces that utilize the carrier assembly 100 inaccordance with several embodiments of the disclosure. Specifically,FIG. 2A is a top plan view of the carrier assembly 100 with a pluralityof semiconductor components 150 attached to the replaceable carrier 130.FIG. 2B is a schematic side cross-sectional view of the carrier assembly100 and the semiconductor components 150 taken substantially along theline 2B-2B of FIG. 2A. Referring to both FIGS. 2A and 2B, the individualsemiconductor components 150 include a microelectronic die 151 and anadhesive 160 (FIG. 2B) on the die 151. The dies 151 include an activeside 152 and a backside 154 (FIG. 2B) opposite the active side 152. Thedies 151 can also include a plurality of terminals (e.g., bond-pads)arranged in an array on one or both of the active side 152 and thebackside 154, and the dies can further have an integrated circuit (shownschematically in FIG. 2B) operably coupled to the terminals. In stillfurther embodiments, the dies can include photosensitive arrays. In theillustrated embodiment, the dies 151 have a height H₁ (FIG. 2B) that isless than a height H₂ (FIG. 2B) of the support structure 110. As such,the dies 151 are received completely within the opening 120 and do notproject beyond the second surface 118 of the support structure 110. Inother embodiments, however, the height H₁ of the dies 151 may be greaterthan the height H₂ of the support structure 110 such that the dies 151project beyond the second surface 118.

The adhesive 160 can be a die attach film or other suitable couplingmember for releasably attaching the backsides 154 of the dies 151 to thereplaceable carrier 130. The adhesive 160 can be disposed on thebacksides 154 of the dies 151 before the dies 151 are attached to thecarrier assembly 100, or the adhesive 160 can be deposited on thereplaceable carrier 130 and then the dies 151 can be attached to theadhesive 160. In either case, the semiconductor components 150 areattached directly to the base 132 such that the adhesive layer 140 isnot positioned directly between the semiconductor components 150 and thefirst major surface 134 of the base 132. Rather, the adhesive 160 of thesemiconductor component 150 is attached to an exposed portion of thefirst major surface 134. The adhesive 140 can accordingly be a firstadhesive, and the adhesive 160 can be a second adhesive with differentproperties than the first adhesive.

In one application, the semiconductor components 150 are attached to thecarrier assembly 100 as part of a wafer reconstruction process. Forexample, the dies 151 can be formed on a semiconductor workpiece andthen the workpiece can be cut to singulate the dies 151. Before or aftersingulation, the individual dies 151 may be tested to detect defectivedies. The known good dies 151 can be attached to the carrier assembly100 for further testing, temporary storage, and/or further processing.The semiconductor components 150 may subsequently be detached from thecarrier assembly 100 for packaging or other processing.

Several embodiments of the carrier assembly 100 illustrated in FIGS.1-2B may increase the time that the assembly 100 can supportsemiconductor components and/or workpieces. Because the first majorsurface 134 of the base 132 includes an exposed section, the adhesive160 of the semiconductor component 150 can be attached directly to thebase 132 without contacting the adhesive layer 140. As a result, theadhesive 160 of the semiconductor component 150 does not bond with theadhesive layer 140 and cause many of the difficulties encountered withconventional carrier tapes. The adhesive 160 may also be selected tohave a lower bonding strength than the adhesive 140 because the adhesive160 only needs to hold a single component 150, but the adhesive 140needs to hold weight of the base 130 and all of the components 150 tothe support structure 110. Therefore, the semiconductor components 150can remain attached to the carrier assembly 100 for an increased lengthof time.

Another embodiment of a releasable carrier 130 for supportingsemiconductor components includes a generally flexible base having afirst major surface and a second major surface opposite the first majorsurface. The first major surface has a first portion sized to carry atleast one semiconductor component and a second portion different thanthe first portion. The releasable carrier 130 further includes anadhesive layer 140 disposed on the second portion of the first majorsurface but not on the first portion of the first major surface. Instill another embodiment, a semiconductor component processing assemblyincludes a semiconductor component releasably coupled to the firstportion of the surface of the flexible base. The carrier assembly 100can be used in the processing of microelectronic dies by attaching theadhesive layer around the perimeter of the replaceable carrier to asupport structure and releasably connecting a die to a base of thereplaceable carrier. The support structure has an opening, and the dieis positioned at least partially in the opening of the support structureand spaced apart laterally from the adhesive layer.

Another embodiment of using the carrier assembly 100 for a method ofprocessing semiconductor components includes providing a semiconductorcomponent having a die with a surface and a first adhesive layer on thesurface. After providing the component, the method further includesreleasably attaching the component to a flexible carrier with the firstadhesive layer contacting a first portion of a base of the carrier. Thecarrier further includes a second adhesive layer on a second portion ofthe base but not on the first portion.

FIG. 3 is a schematic side cross-sectional view of the carrier assembly100 with a semiconductor workpiece 250 attached to the assembly 100. Theillustrated semiconductor workpiece 250 includes a plurality ofmicroelectronic dies 151, an active side 252, and a backside 254opposite the active side 252. In other embodiments, the workpiece 250may include other features in lieu of or in addition to the dies 151. Ineither case, an adhesive 260 releasably attaches the backside 254 of theworkpiece 250 to the first major surface 134 of the replaceable carrier130. The workpiece 250 is positioned such that the adhesive layer 140 ofthe replaceable carrier 130 is outboard and spaced laterally apart fromthe workpiece 250. In other embodiments, a portion of the workpiece 250and/or the adhesive 260 may contact the adhesive layer 140.

The carrier assembly 100 is configured to temporarily support or carrythe workpiece 250 during and/or between processing procedures. Forexample, the carrier assembly 100 may support the workpiece 250 during adicing procedure in which the workpiece 250 is cut with a laser, saw, orother mechanism along lines A-A to singulate the individual dies 151.After singulation, the individual dies 151 can be removed from thecarrier assembly 100 for packaging or other processing.

FIG. 4 is a schematic side cross-sectional view of a carrier assembly300 in accordance with another embodiment of the disclosure. The carrierassembly 300 is generally similar to the carrier assembly 100 describedabove with reference to FIGS. 1A-3, except that the illustrated carrierassembly 300 further includes a second replaceable carrier 330releasably attached to the support structure 110. The second replaceablecarrier 330 can be similar or identical to the first replaceable carrier130. For example, the illustrated second replaceable carrier 330includes a base 332 and an adhesive layer 340 on a portion of the base332. The base 332 can be a generally flexible film having a first majorsurface 334 facing the support structure 110 and a second major surface338 opposite the first surface 334. The first major surface 334 has acentral portion 336 a and a generally annular perimeter portion 336 boutboard the central portion 336 a.

In the illustrated embodiment, the adhesive layer 340 is disposed on theperimeter portion 336 b of the first major surface 334 and attaches thebase 332 to the second surface 118 of the support structure 110.Although the adhesive layer 340 is not disposed on the central portion336 a of the first major surface 334 in the illustrated embodiment, inother embodiments the adhesive layer 340 may cover the entire firstmajor surface 334. In either case, the second replaceable carrier 330can be releasably attached to the support structure 110 after theworkpiece 250 is coupled to the first replaceable carrier 130. Together,the support structure 110 and the first and second replaceable carriers130 and 330 define an enclosed chamber 390 within which the workpiece250 is positioned. The enclosed chamber 390 accordingly protects theworkpiece 250 from contaminants and/or damage.

FIG. 5 is a top plan view of a carrier assembly 400 for processingsemiconductor workpieces in accordance with another embodiment of thedisclosure. The illustrated carrier assembly 400 is generally similar tothe carrier assembly 100 described above with reference to FIGS. 1A and1B. For example, the carrier assembly 400 includes a support structure110 and a replaceable carrier 430 releasably attached to the supportstructure 110. The illustrated replaceable carrier 430, however,includes an adhesive layer 440 disposed on some of the central portion136 a of the first major surface 134 in addition to the perimeterportion of the first major surface 134. Specifically, the adhesive layer440 includes a plurality of apertures 442 that expose sections of thefirst major surface 134. The illustrated apertures 442 have arectangular configuration that can correspond to the size of thesemiconductor components 150 illustrated in FIGS. 2A and 2B. Theapertures 442, for example, can be slightly larger than thesemiconductor components that are to be mounted in the apertures 442. Assuch, the semiconductor components 150 may be placed in correspondingapertures 442 and releasably attached directly to the first majorsurface 134 without contacting the adhesive layer 440. In otherembodiments, the apertures 442 can have a different configuration and/orsize. In additional embodiments, the adhesive layer 440 can be disposedon the base 132 in a different arrangement.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from theinvention. For example, many of the elements of one embodiment can becombined with other embodiments in addition to or in lieu of theelements of the other embodiments. Accordingly, the invention is notlimited except as by the appended claims.

1-19. (canceled)
 20. A method for processing microelectronic dies, themethod comprising: attaching an adhesive layer of a replaceable carrierto a support structure having an opening; and releasably connecting adie to a base of the replaceable carrier with the die positioned atleast partially in the opening of the support structure and spacedlaterally apart from the adhesive layer.
 21. The method of claim 20wherein attaching the replaceable carrier to the support structureoccurs before releasably connecting the die to the replaceable carrier.22. The method of claim 20, further comprising decoupling the die fromthe replaceable carrier.
 23. The method of claim 20, further comprisingdetaching the replaceable carrier from the support structure.
 24. Themethod of claim 20 wherein the replaceable carrier comprises a firstreplaceable carrier, and wherein the method further comprises:decoupling the die from the first replaceable carrier; detaching thefirst replaceable carrier from the support structure; and releasablyconnecting a second replaceable carrier to the support structure inplace of the first replaceable carrier.
 25. The method of claim 20,further comprising releasably connecting a semiconductor workpiece tothe base of the replaceable carrier with the workpiece positioned in theopening and spaced apart from the adhesive layer, the workpieceincluding the die.
 26. The method of claim 20 wherein the die comprisesa first die, and wherein the method further comprises: releasablyconnecting a semiconductor workpiece to the base of the replaceablecarrier with the workpiece positioned in the opening and spaced apartfrom the adhesive layer, the workpiece including the first die and aplurality of second dies; and cutting the semiconductor workpiece tosingulate the first and second dies while the workpiece is connected tothe replaceable carrier.
 27. The method of claim 20 wherein: attachingthe replaceable carrier to the support structure comprises aligning anexposed surface of the base with the opening; and releasably connectingthe die to the base comprises releasably coupling the die to the exposedsurface of the base.
 28. The method of claim 20 wherein: the basecomprises a surface with a first portion and a second portion; theadhesive layer covers the second portion of the surface but not thefirst portion of the surface; and attaching the adhesive layer of thereplaceable carrier to the support structure comprises aligning thefirst portion of the surface with the opening in the support structure.29. The method of claim 20 wherein attaching the replaceable carrier tothe support structure comprises positioning the replaceable carrieracross the opening of the support structure.
 30. The method of claim 20wherein: the replaceable carrier comprises a first replaceable carrier;and the method further comprises releasably coupling a secondreplaceable carrier to the support structure with the die positionedbetween the first and second replaceable carriers.
 31. A method forprocessing semiconductor components, the method comprising: covering atleast a portion of a surface of a semiconductor component including adie with a first adhesive; and releasably attaching the component to aflexible carrier with the first adhesive contacting a first portion of abase of the carrier, wherein the carrier further comprises a secondadhesive on only a second portion of the base apart from the firstportion.
 32. The method of claim 31, further comprising detaching thecomponent from the flexible carrier.
 33. The method of claim 31, furthercomprising releasably connecting the flexible carrier to a supportstructure before releasably attaching the component to the flexiblecarrier.
 34. The method of claim 31 wherein: the semiconductor componentcomprises a first semiconductor component; and the method furthercomprises releasably attaching a second semiconductor component to theflexible carrier after releasably attaching the first component to theflexible carrier but before detaching the first component from theflexible carrier.